The Martial Law Order issued on May 19, 1949 was not a temporary emergency measure, but a long-term mechanism of governance that penetrated every aspect of Taiwanese society. Martial law granted the military, intelligence agencies, and the government almost unlimited power, ushering Taiwan into an era that appeared peaceful on the surface yet was deeply repressive underneath.

During martial law, the constitution was effectively suspended. Military authority took precedence, and “national security” became the highest legal principle. The constitution was treated as being “deferred,” military courts were allowed to try civilians, and searches, arrests, and interrogations could be conducted without warrants. All assemblies, associations, publications, and speeches required prior approval. The government could arrest civilians at any time under the pretext of “endangering national security.” Under such a legal structure, “illegality” ceased to be an objective standard and instead depended on whether the state perceived someone as “dangerous.” The government could do virtually anything; the people could not do anything that might arouse suspicion.

The Taiwan Garrison Command stood at the center of this era, possessing more authority than the Executive Yuan. It controlled publication censorship, household registration and immigration, surveillance, intelligence gathering, interrogation, ideological control in schools and universities, and dual oversight of both military personnel and civilians, as well as the cracking of underground networks and the handling of political cases. According to oral histories and research, the authorities at times deployed large-scale intelligence and surveillance measures, including household monitoring. Families were required to register members, residence conditions, kinship ties, occupations, and even political tendencies.

Military training instructors—often tied to the security apparatus—were stationed in high schools and universities. Their role was to monitor student organizations, vet lectures and campus activities, keep records of students’ political leanings, and report “suspicious remarks.” This fostered an atmosphere of mutual distrust between students and teachers. Factories, schools, and government offices also had volunteer informants. Newspapers, books, plays, films, and advertisements could not be freely produced. Print media operated under fixed quotas; new newspapers could not be founded. All publications had to be submitted for review before release. Even songs and advertising copy could be banned. Overseas publications arriving in Taiwan were subject to inspection. Nearly all public narratives could only exist within the ideological boundaries required by the regime.

Under martial law, curfews were imposed at night, documents were checked at roadblocks, letters could be opened, and travel abroad was nearly impossible. Political discussion in public was prohibited, and even within families, political talk was confined to whispers behind closed doors. The government promoted Mandarin as the national language, and the use of Taiwanese, Hakka, or Indigenous languages was prohibited in schools and many public settings. Local languages and cultures became marginalized. History education emphasized: “We are the Republic of China; we must retake the mainland.” Taiwanese local memory, the Japanese colonial experience, and native ethnic narratives were systematically suppressed.

Martial law entrenched a party-state system in which only the Kuomintang and a few token satellite parties existed. Central representatives served virtually for life, opposing parties were illegal, elections were tightly controlled, and the media was thoroughly KMT-dominated. Political dissent did not lead to debate—it led to arrest.

Several cases from this period caused widespread shock. One was the Lei Chen case. Lei, the founder of Free China magazine, was a moderate and rational liberal who advocated constitutional reform and anti-corruption measures to move Taiwan toward genuine democracy. Under martial law, Free China was forcibly shut down, and Lei was arrested on charges of being a “Communist agent,” ultimately receiving a ten-year sentence. In the Taiwan University Mathematics Department case, several students, teaching assistants, and professors were targeted simply for discussing politics, reading leftist books, or corresponding with one another. Some students were arrested, and some professors were forced to leave Taiwan, leaving the entire department under a cloud of fear for years. Many political cases of the era mixed fabricated espionage charges with guilt by association.

In 1980, the family of lawyer and opposition leader Lin Yi-hsiung was brutally murdered in broad daylight—his mother and twin daughters were killed while his home was supposedly under Garrison Command surveillance. The case remains unsolved, and many believed it was a political assassination meant as a warning. In 1981, Chen Wen-chen, a scholar who had participated in Taiwanese democracy movements overseas, was summoned by the Garrison Command during a visit home. The next day, his body was found on the National Taiwan University campus. The official claim of suicide was riddled with inconsistencies.

From the 1970s to the 1980s, the United States gradually shifted from supporting anti-communist authoritarian regimes to promoting global democratization. The Carter administration, human-rights diplomacy, and the loosening of authoritarian rule in South Korea and the Philippines influenced Taiwan. At the same time, expanded education, the rise of the middle class, and rapid urbanization transformed Taiwanese society. Economic takeoff produced new social structures: university graduates increased, city life exposed people to more information, and workers began developing a sense of labor consciousness. Journalists also grew resentful of censorship. Martial law attempted to preserve the social order of the 1950s, but Taiwan of the 1970s and 1980s was no longer that Taiwan.

By the late 1970s, opposition forces emerged outside the KMT. Independent candidates appeared in elections; lawyers, journalists, and professors formed political networks; and local social movements—including environmental, labor, linguistic, and cultural movements—began to grow. The opposition magazine Formosa became a hub for political thought.

In 1979, Formosa held a Human Rights Day rally in Kaohsiung, openly challenging one-party rule. Although the event had been legally registered, it escalated into the most significant confrontation of the martial law era. Held at the traffic circle on Zhongzheng Road, it drew thousands from across southern Taiwan. Labor and student groups quietly joined, and major opposition leaders—including Huang Hsin-chieh, Shih Ming-te, Yao Chia-wen, Kang Ning-hsiang, Chang Chun-hung, Chen Chu, and Lin Yi-hsiung—were all present. It was the first public display of opposition on such a scale.

The government had prepared extensively: heavy police presence surrounded the area, plainclothes agents mingled in the crowd, and intelligence units closely monitored all opposition figures. As Formosa leaders addressed the crowd, tensions escalated. Police cited “traffic disruption” and “improper permits,” cut the sound system, and ordered dispersal. They soon fired tear gas and advanced with shields. Protesters responded by throwing objects and signs. Violent clashes erupted—scenes rarely seen under martial law—resulting in injuries on both sides.

The regime immediately labeled the demonstration a “violent rebellion” and a “Communist-inspired subversive movement.” Beginning December 13, Formosa offices were raided, and nearly all opposition leaders were arrested and transferred to military courts. The trials were closed to the public, with no outside access. Prosecutors charged the defendants with “sedition,” “organizing violent revolution,” and “attempting to overthrow the government.” International media, Western governments, and human-rights organizations condemned Taiwan; the U.S. Congress applied pressure; Amnesty International intervened; and academics worldwide voiced support.

Caught between preserving authoritarian control and the risk of international isolation, the KMT faced mounting pressure. Several defendants received life sentences or long prison terms—Shih Ming-te was sentenced to life, and others received 12–14 years. Yet the trial propelled the concepts of “democracy, freedom, and human rights” into Taiwan’s public discourse more forcefully than ever before.

The Kaohsiung Incident made many Taiwanese realize for the first time that dissent is not a crime, and that the pursuit of democracy is possible. The confrontation pushed Taiwan from the illusion of “authoritarian stability” into the dawn of democratization.